Update missing worker binaries error (#2853)

Please let me know if this would be a better UX. Should we have specific
links in the error message?

.github/workflows/check-markdown.yml

@@ -31,4 +31,5 @@ jobs:
         env:
           CONFIG: .github/.markdownlint.yaml
         run: |
+          echo "Checking markdown formatting. More info: docs/contributor/markdown_linting.md"
           markdownlint --config "$CONFIG" --ignore target .

polkadot/README.md

@@ -9,9 +9,11 @@ guides, like how to run a validator node, see the [Polkadot Wiki](https://wiki.p
 
 ### Using a pre-compiled binary
 
-If you just wish to run a Polkadot node without compiling it yourself, you may either run the latest
-binary from our [releases](https://github.com/paritytech/polkadot-sdk/releases) page, or install
-Polkadot from one of our package repositories.
+If you just wish to run a Polkadot node without compiling it yourself, you may either:
+
+- run the latest binary from our [releases](https://github.com/paritytech/polkadot-sdk/releases) page (make sure to also
+  download all the `worker` binaries and put them in the same directory as `polkadot`), or
+- install Polkadot from one of our package repositories.
 
 ### Debian-based (Debian, Ubuntu)
 

polkadot/node/service/src/lib.rs

@@ -239,7 +239,7 @@ pub enum Error {
 	InvalidWorkerBinaries { prep_worker_path: PathBuf, exec_worker_path: PathBuf },
 
 	#[cfg(feature = "full-node")]
-	#[error("Worker binaries could not be found, make sure polkadot was built/installed correctly. If you ran with `cargo run`, please run `cargo build` first. Searched given workers path ({given_workers_path:?}), polkadot binary path ({current_exe_path:?}), and lib path (/usr/lib/polkadot), workers names: {workers_names:?}")]
+	#[error("Worker binaries could not be found, make sure polkadot was built and installed correctly. Please see the readme for the latest instructions (https://github.com/paritytech/polkadot-sdk/tree/master/polkadot). If you ran with `cargo run`, please run `cargo build` first. Searched given workers path ({given_workers_path:?}), polkadot binary path ({current_exe_path:?}), and lib path (/usr/lib/polkadot), workers names: {workers_names:?}")]
 	MissingWorkerBinaries {
 		given_workers_path: Option<PathBuf>,
 		current_exe_path: PathBuf,